The W124 500E/E500 was sold in the US for model years 1992-1994. It was compared to the M5 of it's day, not the new 394hp M5.
Going up against it's contemporaries, the W124 E500 is a winner. It lacks some of the edge of the M5, but is much more reliable, cheaper to maintain, and has held it's value much better.
An M6 can be one expensive car to own. M parts are $$$$$$$! Most of the E500 is off the shelf bits and not unique "racing" parts like M engines.
1998 C230 "Black Betty"